But the day could have been markedly different for Australia had wicket-keeper Brad Haddin not dropped a regulation catch behind the stumps when Root was yet to get off the mark.

Root was dropped by the keeper on just his second ball as he edged Starc behind, and he went on to punish the tourists with a sublime innings.

Ashes newcomer Josh Hazlewood (3 for 70) and left-armer Mitchell Starc (3 for 84) were the pick of Australia's bowlers, though it was a day of toil and mixed fortunes for Mitchell Johnson (0 for 87).

Things started shakily for the hosts as Josh Hazlewood made his first inroads in Ashes cricket with the dismissal of opener Adam Lyth (6), who tentatively edged to David Warner in the slips.

England skipper Alastair Cook looked to establish the innings, playing three crisp shots for elegant boundaries, but he fell for 20 when he went after a short and wide Lyon (1 for 54) delivery, edging his cut shot straight to Brad Haddin.

Ian Bell lasted just seven deliveries before he fell for 1, trapped lbw to an excellent Mitchell Starc swinging yorker.

Subscribe to get ABC News via email, including Grandstand reports and analysis of each day's play, plus top news, opinion and alerts on major breaking stories.

But stability and elegance arrived in the form of Root, who set about resurrecting England's innings with a dashing innings.

Root shook off the early chance which Haddin grassed, punishing anything short with cuts and pulls that had Cardiff sensing a comeback, while Ballance provided stout support as the pair successfully guided England to lunch at 3 for 88.

The partnership extended past 100 runs as first Root, then Ballance reached their half-tons in a chanceless second session as the pair guided the hosts to 3 for 190 at tea.

Ballance fell when he was trapped leg-before by Hazlewood, but Root would reach his century off 118 balls, having struck 14 boundaries, as England passed the 200 mark for the loss of just four wickets.

Starc removed the centurion Root on his first ball back for a new spell, procuring an edge off the off-drive as Shane Watson dived low for a sharp catch in the slips.

Stokes came to the crease and showed his intent early on, hitting six fours and two sixes - both against Nathan Lyon as he took the attack to the off-spinner - as he reached a half-ton in 76 balls.

Stokes had only just seemed to have raised his bat, however, when he was clean bowled by a beauty from Starc, who got the ball to move away from the left hander and rattle the middle stump.

Jos Buttler (27) and Ali combined for a 50-run partnership for the seventh wicket as both batsmen played their shots, with Ali in particular getting off to a lightning-quick start, thanks to a crisply-struck slog-sweep off Lyon for six.

Buttler was dismissed tamely, spooning a slower ball of Hazlewood's to Johnson at mid-wicket, before Stuart Broad navigated the last over without trouble to close out the day.